Variable pressure cushion system



Sept. 29, 1959 R. ADIAIR, JR

VARIABLE PRESSURE CUSHION SYSTEM.

Filed May 22, 1956 2 SheetS- Shee l R. ADAIR, JR

VARIABLE PRESSURE CUSHION SYSTEM Sept. 29, 1959 2 Sheets-Sheet 2 Filed May 22, 1956 United States Patent This invention relates to a variable pressure cushion system and more particularly to a structure which may be employed in any of several different applications, one

of which is fulfilling the requirements of an invalids bed in which operable means are provided periodically to relieve the body-supporting pressures thereby to enhance the comfort of an occupant.

In still another aspect, the invention relates to a cushion structure which may be articulated for varying the relative attitudes of different segments thereof while maintaining the operability of the variable pressure means ineach segment.

In prior application Serial No. 496,541, now Patent No; 2,790,440, filed March 24, 1955 for a Variable Pressure Cushion, applicant has disclosed a system in which alternate elements in a series of slat-like cushions are rotated. about a pivotal axis to vary pressure points on an occupant of the structure. However, it has been found that an improved supporting and actuating system such as provided in the present invention is superior in providing the therapeutic values to a patient or other occupant over long periods.

In accordance with the present invention there is provided a variable pressure cushion which comprises a frame having a series of transversely extending cushions each of which is substantially shorter than the width of the frame. Supporting means are provided at each end of each of the cushions which in turn are pivotally supported from the frame members for rotational movement thereof about transverse axes which extend parallel to said cushions but which are displaced along the length of said frame a distance substantially greater than the width of each cushion. Common linkages are provided extending along each side of said frame and interconnecting alternate supporting means. A pair of shafts supported by said frame are rotatably coupled to said linkages for selectively imparting rotation to the supportingmeans.

r In a preferred embodiment of the invention means are provided for automatically actuating a control system in a predetermined time sequence for selectively positioning one or the'other of said sets of cushions in a body-supporting plane and for moving the other of said sets of cushions away from said plane only after the first of said sets is in said plane.

For further objects and advantages of the invention and for a more complete description thereof, reference may now he had to the following description taken in conjunction with the accompanying drawings in which:

Fig. l is a side view of the invention as embodied in an articulated hospital bed and includes a diagram of an automatic control system therefor;

Fig. 2 is a sectional view of the head section of the bed of Fig. 1 taken along the lines 22 of Fig. 1 when in recliningposition;

Fig. 3 is an isometric view of the linkage system for one end of each of four of the cushions of Fig. 1;

2,906,259 Patented Sept. 29, 1959 Figs. 4, 5 and 6 are three views of the cushion sup porting means;

Fig. 7 is a time plot of a control program; and

Fig. 8 is a modification of the invention.

Referring now to Fig. 1, a side view of a hospital bed embodying the. present invention is illustrated as comprising a bed supporting frame 10 (which has been shown partially dotted for the purpose of clarity) which, it will be understood, forms a part of a bed frame which is provided with the usual legs at the head and foot thereof. As indicated the present invention comprises a variable pressure cushion which not only is unique in and of itself but which finds ready application as' a part of an articulated hospital bed in which a person may be fully recumbent or prone; may have the head section only elevated; or, in addition to elevation of the head section, may have the knee. section raised to provide such variations in position as may be desired. At the same time the body-supporting means of each such section may be varied to support the body alternately at different points in accordance with a predetermined program.

In connection with the. latter operation, alternately positioned cushion segments are selectively moved into and away from body-supporting planes without altering the normal position of the body. More particularly, control and actuating means are provided whereby a first set of cushions alternately positioned with a second set of cushions in a body-supporting plane will be moved into said plane prior to any movement; of the second set of cushions from said plane. Such action permits the application of variable supporting pressures to patients in traction and the like where variation in the position of the body-supporting plane could not be tolerated. A control system provided by the present invention will permit the selection of a program in which pressures are varied at different points in a body-supporting plane during a first time interval which time interval may then be followed by a predetermined time interval in which both sets of supporting cushions are positioned in said plane to provide a substantially continuous body supporting cushion. The foregoing operative features of the present invention may better be understood by referring to the following detailed description of the struc ture illustrated in the drawings.

The articulated body-supporting segments of the hospital bed of Fig. l are supported from frame 10 by posts 11 and 12 which are suitably secured to frame 10. Post 11 has been broken away along the lower section thereof in order to permit illustration of the actuating means for the rump section of the bed. Support 12 is secured to frame 10 as by rivets, welding or other means. The head section of the bed comprising frame 13 and the curved hinge section 14 is adapted to be pivoted about pin 15. The upper end of section 13 may be supported by means not shown but well known in the art. Such means ordinarily are embodied in hospital beds and provided with actuating means selectively to elevate and lower the head section. In Fig. 1, while no such means is shown, the head section is illustrated in an elevated position.

The rump section of the bed including a frame member 16 is rigidly secured either to post 11 or to frame 10. As illustrated in the drawings, rivets such as rivets 17 are provided for securing frame member 16 to post 11.

The thigh section of the bed is comprised of three frame members 18, 19 and 20. Member 19 is secured to member 18 which is pivoted to post 12 and thereby permits rotation of the thigh section about pin 21. The upper end of member 19 is secured to hinge member 20 which is provided with a pivot pin 22.

The section for supporting the lower leg comprises a frame member 23 which is pivoted on pin 22 and thereby attached to member 20. The lower end of frame 23 is supported by frame 10. The latter support may be of the form ordinarily found in hospital beds. However, for the purpose of the present description a roller 24 mounted on a stub shaft 25 extending outwardly from frame 23 rests on the upper surface of the frame member to permit the thigh and lower leg portions to be jackknifed or folded to the position shown in Fig. 1.

Frame members 13, 16, 19 and 23 each support two sets of independently actuated body-supporting cushions which are in'the form of relatively narrow slats extending transversely across the bed. It is understood that the exact counterpart or mate for each of the elements 10- 25 above described is provided at the side of the bed opposite that shown in the View of Fig. 1 and together with elements 10-25 form the frame elements that will hereinafter be discussed. The head section comprising frame 13 includes 16 transverse cushions, eight of which, the cushions 30, are shown elevated in a body-supporting plane. Cushions lowered from the body-supporting plane to a position behind member 13 ordinarily occupy the spaces between cushions 30. Similarly, cushions 31 in a body-supporting position are supported by frame member 16. Intermediate cushions lowered from the body-supporting plane are also supported by frame 16. Similarly, frame 19 is provided with cushions 32 and frame 23 is provided with cushions 33. Each of sections 13, 16, 19 and 23 is provided With independent actuating means for controlling the positions of the cushions. More particularly, in the embodiment illustrated, section 13 is pro vided with a pair of doubly actuated, hydraulic cylinders 40 and 41. Cylinders 40 and 41 are supported from frame 13 as by means including brackets 42 and 43, respectively. A pair of shafts 44 and 45 supported by brackets from frame 13 are coupled by arms 46 and 47, respectively, to the cylinder shafts 48 and 49, respectively. Pneumatic lines 50 and 51 extend from cylinder 40 to a valve 52. Pneumatic lines 53 and 54 extend from cylinder 41 to a valve 55. The selective application of fluid pressure to lines 50, 51 and 53, 54- actuates pneumatic cylinders 40 and 41 to control the positions of the cushions supported by frame 13.

In a similar manner frame member 16 supports pneumatic cylinders 60 and 61; frame member 19 supports pneumatic cylinders 62 and 63; and frame member 23 supports pneumatic cylinders 64 and 65 for the control and actuation of their respective cushions. Pneumatic cylinders 40, 60, 62 and 64 are all controlled or actuated from pneumatic lines 50 and 51 in response to the position of valve 52. Similarly, pneumatic cylinders 41, 61, 63 and 65 are actuated and controlled by pneumatic lines 53 and 54 in response to the position of valve 55.

From the foregoing it will be recognized that there are provided eight sets of cushions, two sets to each of the sections comprising frames 13, 16, 19 and 23. Also there are similarly provided eight pneumatic actuating means which operatively connected to two hydraulic systems simultaneously actuate four sets of cushions, one set in each section. Each of sections 16, 19 and 23 is provided with shafts corresponding with shafts 44 and 45, their supporting means and linkages.

In referring to the supporting means for cylinders 40 and 41 and shafts 44 and 45, it should be understood that the cylinders preferably are positioned near the center of the frame with the supports for the shafts at the edges of the frame.

More particularly referring to Fig. 2, the frame 10 is illustrated as comprising an L-shaped member. Frame member 13 comprises a channel. Shaft 45 extends across the bed and is supported by a bracket 68 on the left hand side. Bracket 68 is secured as by welding to the lower flange of frame member 13. Similarly, a shaft supporting bracket 68a is welded to the lower flange of the frame member 13a on the right hand side of the bed as viewed in Fig. 2.

A bar or frame member 69 secured to the lower flanges of frame members 13 and 13a extends across the bed to provide a support for the cylinder 41. More particularly, bracket members 43 and 43a are secured to bar 69 as by welding. Cylinder 41 is mounted on trunnions 70 and 71 at the lower end of the brackets 43 and 43a to permit the slight rotation of cylinder 41 necessary for rotation of shaft 45. More particularly, shaft 45 is coupled to the cushion supporting brackets by means including crank arms 75 and 76. As shown in Fig. 2, crank arms 75 and 76 are mounted on oposite ends of shaft 45 and extend upwardly through slots in the lower flanges of the channels 13 and 13a.

It is understood that similar brackets and supporting means will be provided for shaft 44 and for supporting the bracket arms 42. and 42a upon which the cylinder 40 is trunnion mounted.

The actuating means for the supporting cushions may best be understood by referring to Figs. 3-6. Fig. 3 is an isometric view of a portion of four adjacent variable pressure cushions together with the mounting brackets therefor and a portion of the actuating linkage. More particularly, cushions 81, 82, 83 and 84 are shown with their upper surfaces in the same plane and in a plane which has heretofore been referred to as a body-supporting plane. Each of the cushions 81-84 is provided with an end supporting arm such as arm 85 which supports cushion 81. Arm 85 is shown in detail in the three views of Figs. 4-6. Arm 85 is supported on the frame member above-discussed in connection with Fig. 1 for rotation about axis 86. The arm as shown in Figs. 4-6 is provided with an upper anchor pin bearing 87 which is bored to receive a pin or bolt which will be secured to frame 13, Fig. 1. As seen in Figs. 5 and 6, arm 85 is provided with a depending section which terminates in a second bearing 88. As seen in Fig. 5, with the cushion 81 horizontal and in a body-supporting plane a line passing through the center of bearings 87 and 88 is slightly angular with respect to a vertical line. In practice the angle 89 has been made to be about 11. As seen in Figs. 46, the bearing 87 is substantially longer than hearing 88. As seen in Fig. 6, a section 90 extends from bearings 87 and 88 and terminates in a face supporting plate 91. It should be noted in the top View, Fig. 4, that the axis 87a of bearing 87 is parallel to the center line 81a of the cushion 81 and as shown is substantially spaced therefrom by a distance X. Preferably the spacing X is at least twice or three times the width of cushion 81. As shown in Fig. 5, the axis 87a of bearing 87 is slightly below the top of the cushion 81. As seen in Fig. 6, the end 81b of cushion 81 is spaced inwardly of the frame member 13 which has been shown dotted. Preferably the distance Y is approximately the same dimension as the width of cushion 81. By providing the proper relationship between distances X, Y and the Width and depth of cushion 81, alternate cushions in a series may be moved along arcuate paths into and out of the body-supporting plane without interference with the adjacent cushions and at the same time require but a minimum of space or void between adjacent cushions.

Referring to Figs. 5 and 6, it will be seen that foam rubber cushion 81 is secured to the upper surface of a thin-walled rectangular tube 95. The tube supporting plate 91 of arm 90 is positioned in the end of the tube 95 and secured thereto by suitable means. For example, a pin or screw 96, Fig. 5, may be inserted through the wall of tube 95 into. the plate 91. To facilitate assembly, the lower wall of tube 95 is preferably cut away over the length 97 so that the cushion members may conveniently be dropped onto the cushion supporting plate 91.

In practice it has been found preferable to secure the cushion 81 to the upper surface of tube 95 by the use of material such as marketed by Minnesota Mining Company under the designation of EC 971 Water Dispersion Adhesive. Qther adhesives may also be found suitable.

Referring to Fig. 3, it will be seen that with the arm 85pivoted from a frame for rotation about axis 86, the lower bearing 88' is secured to a push bar 100. Push bar 100 secured by a pin- 101 to the lower bearing 88. Similarly, push bar 100 is secured to the lower bearing in arm 102. Translation of the push bar 100 in the direction of arrow 103 of but small magnitude will rotate arms 85 and 102 about axes 86 and 104 to drop cushions 81 and 83 from the body-supporting plane. By reason of the above-mentioned dimensions of the brackets and cushions, the cushions 81 and 83 may be rotated completel'y away from the body-supporting plane without interference with cushions 82 and 84.

In a similar manner cushions 82 and 84 are mounted onarms 105- and 106 which in turn are supported from a frame for rotation about axes 107' and 108, respectively. The lower bearings of brackets 105 and 106 are coupled to a push bar 109 which upon movement in the direction of arrow 110 will rotate cushions 82 and 84 from the body-supporting plane. The bell crank 68 coupled to shaft 45 is provided for actuating bar 109 in direction of arrow 110. The translational motion of the plunger 49 of the pneumatic cylinder 41 produces the rotational movement of shaft 45. While only one pneumatic cylinder and shaft with its associated linkages have been shown in Fig. 3, it is understood that an additional cylinder, shaft and linkages as shown in Fig. 1 will be provided for actuating bar 100. It is further understood that a similar set of linkages will be provided for the side of the bed or cushion opposite the side shown in detail in Fig. 3. Such linkages are shown at the right hand side of the. detailed sectional view of Fig. 2.

Having described the mechanism by which the transverse, slat-like cushions may be moved into and out of a body-supporting plane either in an articulated bed structure or in other cushions provided for a body support, there will now be explained an electrical system by which the aforesaid operations may be carried out in accordance with any one of a number of predetermined programs.

More particularly referring to Fig. 1, there is illustrated a motor 150 which is energized by conductors 151 and 152 which lead to a plug 154 which in turn may be connected to any suitable convenient outlet of proper voltage. A switch 155 is provided selectively to energize the entire system. Motor 150 isconnected by shaft 156 to a fluid pump 160. Pump 160 is. connected to a reservoir 161 and is adapted to employ fluid in reservoir 161 to pressure an output line 162. The output line 162 has a first branch 163 which leads to valve 52. A second branch 164 leads to valve 55. A fluid return is provided leading to reservoir 161 and comprises a first branch 165 leading from valve 52 and a second branch 166 leading from valve 55. With the valves 52 and 55 in the position shown, lines 51 and 54 are under pressure. As a result, the piston in cylinder 40 is fully retracted and the piston in cylinder 41 is fully extended, whereby cushions 30 under the control of piston 41 are in a body-supporting plane and alternate cushions. not shown, but under the control of cylinder 40, are lowered substantially below said plane. At the same time. fluid from lines 50 and 51 drains through valves 52 and 55 into branches 165 and 166,. respectively, and thence to the return line 167 leading to reservoir 161. With valves 52 and 55 rotated through 90, lines 50 and 53 are under pressure thereby to extend the piston of cylinder 40 and to retract the piston of cylinder 41. The latter action would lower the cushions 30 from the body-supporting plane and raise cushions under control of cylinder 40 into the body-supporting plane.

It is important that the latter operation be accomplished while maintaining unaltered the position of the body-supporting plane. This is done by suitably controlling valves 52 and 55 as through solenoids 200 and 201, respectively. The system shown in Fig. 1 provides for three separate programs for the operation of solenoids 200 and 201.

.solenoid 201.

There will first be described a systemin which cushions are alternately raised and lowered at 5- minute intervals. More particularly, a timer motor 202 is connected atone terminal to line 151 and at a second terminal is connected by way of conductor 203 to a first terminal of a two pole switch 204. The arm of switch 204 is connected to terminal 205 of a two pole switch 206. The arm of switch 206 is connected to conductor 152. I

With the arms of switches 204 and 206 in the position shown, motor 202 is energized. A shaft 207 is connected to drive cams 208 and 209'. Cam 208 operates to open and close switch 210. Cam 209 operates to open and close switch 211. The cams 208 and 209 are adjusted on shaft 207 such that switch 210 will be closed for a predetermined time interval, for example approximately five minutes, and switch 211 will be open for approximately the same interval. However, in order to assure that the body-supporting plane will remain unchanged, it is necessary that both switch 210 and switch 211 be closed for short periods of time during the transition. In Fig. 7 there is plotted the time sequence of the closure of switches 210 and 21 1. The upper line 220 shows the periods during which switch 210 is open and closed. Similarly line 221 shows periods during which switch 211 is open and closed. It is important to note that for a small interval of time 222 both switches are closed in each cycle of operations. During interval 222 all of the body-supporting cushions will be in an elevated position such as shown in Fig. 3. With either switch 210 or 211 open, selected ones of the body-supporting cushions will be removed from the body-support ing plane.

More particularly, when switch 210 is closed, solenoid 201 is energized. The upper terminal of switch 210 is connected by way of conductor 225 to one terminal of The other terminal of solenoid 201 is connected to conductor 151. The movable contact of switch 210 is connected by way of conductor 226 to conductor 152.

Upon energization of solenoid 201, the valve 55 is rotated suitably to vary the application of fluid pressures to the lines 53 and 54. When switch 211 is closed, power from conductor 152 is applied by way of conductor 226 to conductor 227 which is connected to one terminal of solenoid 200. The other terminal of solenoid 200 is connected to conductor 151. When solenoid 200 is energized, valve 52 is rotated 90 to suitably alter the pressures in lines 50 and 51.

The system including motor 200 and cams 208 and 209 was selected in one embodiment of the invention to operate on a 5 minute time sequence with approximate ly 5-10 seconds forming the interval 222. In the same system there was provided a second timer motor 230 operating cams 240 on a 10 minute schedule where cams 240 control switches in circuit with solenoids 200 and 201. Motor 230 is energized when switch 204 is moved to the right hand switch position. Thus by energizing motor 202 or motor 230 under the control of switch 204, 5 minute or 10 minute variations in the bodysupporting plane may be efiected.

By the addition of a third timer motor 250 which controls cams 251, 252, 253 a schedule is provided in which all of the cushions would be maintained in a body-supporting plane for a first time interval which will be followed by a second time interval during which the cushions Would be alternately positioned in the body-supporting plane either on 5 or 10 minute cycles. More particularly, cam 251 controls the switch 255 which applies power by Way of conductor 256 to switch 257.

Switch 257 applies such power either to timer motor 202 (when in the position shown) or to timer motor 230 (when in the left hand position). Cam 251 preferably will be driven to close switch 255 for intervals in the order of half an hour or an hour dependent upon the particular timer motor employed. Cams 252 and 253 control switches 260 and 261. Switch 260, when closed, applies power from conductor 256 to solenoid 201. Switch 261, when closed, applies power from conductor 256 to solenoid'200. With cams 252 and 253 positioned relative to cam 251 so that closure of switches 260 and 261 is effected just prior to the opening of switch 255, then all cushions will be maintained fixed for the period of closure of two switches 260 and 261 and will then be alternately actuated during the period switch 255 is closed' and two switches 260 and 261 are opened. Timer motor 250 will be energized by moving the arm of switch 206 to the right hand position. The entire system will be de-energized, of course, by opening switch 155.

From the foregoing it will be appreciated that great latitude is provided in the particular time program to be adopted to the end of providing the greatest of comfort or to meet the requirements of the best therapeutic program for the occupant of the cushion or bed.

In one embodiment of this invention cylinders 40, 41 were of the type designated as Model A83 manufactured and sold by Miller Fluid Power Company, 2040 N. Hawthorne Avenue, Melrose Park, Illinois.

Valves 52 and 55 were of the type designated as Valvair No. H-24231l0, single solenoid, four way valves manufactured and sold by the Valvair Corporation, 454 Morgan Avenue, Akron 11, Ohio. While in the drawings the valves 52 and 55 are shown separate and apart from solenoids 200 and 201, the above identified Valvair units embody actuating solenoids that may be made responsive to a given control program. In the form shown in Fig. 1, it will be understood that valves 52 and 55 are of the type that have a normal position and are rotated through 90 to a second position. A suitable spring on each valve may be employed to return the valve to the normal position when the solenoids are de-energized. Alternatively, the solenoids may be energized but momentarily to actuate the valves in a stepwise fashion, thus reducing power requirements on the system while retaining all the desirable features of the program indicated in Fig. 7.

In Fig. 1 the motor is energized when switch 155 is closed and thus may run continuously. A relief valve 300 is connected between the output of the pump and the return to the reservoir 160. When cylinders 40 and 41 are in either extreme position, excessive pump pressure on the lines 50, 51 and 53, 54 is relieved by valve 300. It will be readily apparent that motor 161 may be operated intermittently and in synchronism with solenoids 200 and 201 if desired. Also note that switch 155 may be opened when all slats are in a body-supporting plane thereby to provide a continuous non-varying support.

The timing systems such as actuated by timer motors 202, 230 and 250 were of the type manufactured and sold by Eagle Signal Corporation of Moline, Illinois and known as poly-pulse timers.

It should be noted that all elements of the electrical system of Fig. 1 are to be enclosed in an explosion-proof housing and mounted on the supporting frame forming the foot of the bed structure. In that case only the four pneumatic lines and one electrical cable would lead from the housing. All necessary precautions relative to safety may thereby be met.

In the foregoing reference has been had to transverse slats and a frame of described width and length. It will be apparent that it may be desirable to place the slats lengthwise of the bed in which case the foregoing descriptive terms Will be understood to pertain to such structure in the same manner as to the preferred embodiment in which the slats are transverse to the bed.

While the invention embodied in a hospital bed has been described, it will be appreciated that other embodiments will be useful. One such embodiment is shown in Fig. 8 in which a seat for use in an automobile,

truck or other vehicle is shown. Drivers, pilots and the 7 like are often required to occupy' a seat for extended periods of time, resulting in fatigue. The provision of a seat shown in Fig. 8 will provide relief in that cushion slats 301 are mounted on frame members 302 and 303 which in turn are supported on a base 304. Additional cushion slats, lowered from the plane of the upper face of slats 301, are adapted to be raised to fill the spaces between slats 301. In the embodiment of Fig. 8, as in Fig. 1, a series of elongated cushion slats are disposed normally in a side-by-side relation. Arms rigidly secured to each end of each slat are of length greater'than the slat width. The arms are pivotally mounted at the ends thereof opposite the connections to the slats. The frame members 302 and 303 are adapted to provide such pivot means, providing axes of rotation parallel to the slats and positioned relative thereto a distance substantially in excess of the slat width whereby each slat may traverse an arc of substantial radius from the plane of the body-supporting surface to a retracted position below said surface. First coupling means will be provided for the arms of odd numbered slats (301). Second coupling means will also be provided for arms of even numbered slats (retracted). Shafts 305 and 306 are adapted to actuate the first and second coupling means, respectively. Control forces may thus be applied intermittently to shafts 305 and 306 as by hydraulic means shown in Fig. l or by motors, etc. to alternately position the odd and even numbered slats in a body-supporting plane, and in any case it is preferable to maintain the normal position of said plane.

Other embodiments may now suggest themselves to those skilled in the art, and it is intended to cover such embodiments as fall within the scope of the appended claims.

What is claimed is:

1. A cushion comprising at least a pair of elongated cushion slats disposed in side-by-side relation with the upper faces thereof forming a body-supporting surface, frame members adjacent the ends of said slats, arms rigidly secured to each end of each of said slats and pivotally mounted on said frame members for rotating said slats in arcuate paths extending below said plane with each path having a center axis parallel to its respective slat but spaced therefrom a distance exceeding the width of said slat, actuating means coupled to the arms on a first of said slats, actuating means coupled to the arms of the second of said slats, and means for intermittently energizing said actuating means for moving said slats alternately into and away from the plane of said surface while maintaining the normal position of said plane.

2. A cushion comprising a series of elongated cushion slats disposed in side-by-side relation with the upper faces thereof forming a body-supporting surface, frame members adjacent the ends of said slats, arms rigidly secured to each end of each of said slats, said arms of length greater than the width of said slats and each pivotally mounted on said frame members at the end opposite said slats for bodily rotating said slats in arcuate paths extending downward from the plane of said surface, a first coupling means interconnecting odd numbered slats in said series, a second coupling means interconnecting even numbered slats in said series, means for alternately actuating said first coupling means and said second coupling means following return to the plane of said surface of said even numbered slats and said odd numbered slats respectively.

3. The system set forth in claim 2 in which control means are provided for the actuating means to program alternate movement of said slats during a first interval and to immobilize said actuating means during a second interval.

4. A body support comprising a series of cushion slats disposed in a side-by-side relation with the upper faces thereof normally forming a body-supporting surface,

frame means, means for mounting said slats on said frame means for pivotally moving said slats about axes parallel to the length of said slats into and away from the plane of said surface, means for articulating said frame intermediate the extremities of said surface for bodily rotating a selected number of said series of slats about axes parallel to said slats, a first pair of actuating means carried by said frame on both sides of said last named axis and coupled to odd numbered slats in said series, a second pair of actuating means carried by said frame on both sides of said last named axis and coupled to even numbered slats in said series, flexible means connecting said first pair of actuating means to an energy source, flexible means connecting said second pair of actuating means to said energy source for controlling movement of alternate slats in said series relative to said plane.

5. A body support comprising a series of cushion slats disposed in a side-by-side relationship with the faces thereof forming a body-supporting surface, frame means, arms for each of said slats for pivotally mounting said slats on said frame means, means for articulating said frame for bodily rotation of a portion of said slats relative to others of said slats about axes extending parallel to said slats, means carried by said frame means on each side of said axis adapted simultaneously to rotate odd numbered slats about axes parallel to said axis, means carried by said frame means on each side of said axis adapted simultaneously to rotate even numbered slats about axes parallel to said axis, means including an energy source independently coupled to each of said actuating means for intermittently and alternately actuating said coupling means.

6. A variable pressure cushion structure comprising a frame, a first set of narrow elongated cushions extending traversely of said frame but substantially shorter than the width of said frame, supports for each end of said cushions, means for pivotally mounting said supports along the edges of said frame for pivotal movement about an axis parallel to said cushions and spaced substantially therefrom, a shaft supported from said frame, means for rotating said shaft, and means for coupling said shaft to each of said supports for selectively rotating said cushions about said axes into and away from a body-supporting plane.

7. A body support having two side frame members, a first set of cushions comprising a plurality of cushion members extending between said frame members and spaced from each other, a second set of cushions comprising a plurality of cushion members extending between said frame members intermediate the cushion members of said first set with the upper faces of said cushions forming a body-supporting surface, supporting means at each end of each of said cushions for pivotally mounting said cushions for rotation about axes parallel thereto but spaced substantially therefrom, a first shaft and a second shaft extending between said frame members and supported therefrom, and means for independently coupling said first set and said second set of cushions to said first and second shafts respectively, means for rotating said shafts independently to rotate said first set and said second set of cushions about said axes into and away fromthe plane of said surface.

References Cited in the file of this patent UNITED STATES PATENTS 1,643,793 Sparhawk Sept. 27, 1927 2,445,158 Sparhawk July 13, 1948 2,461,102 Ackerman Feb. 8, 1949 

